Both in the case of walkways and mechanical stairs, either the moving platform for transporting persons or objects or the steps, move accompanied in a synchronized manner by a handrail aiding in the corporal stability of the user when it is driven by the moving surface on which it rests.
There are different structural solutions for the actual handrail, one of such solutions consisting of an alignment of handgrip-carriages, which at the end of the walkway or of the mechanical stairs are concealed under a fixed structure or railing, where said handgrip-carriages undergo a 180° C. inflexion in their path, to again return to the start of the walkway or stairs, carrying out this return path in a concealed condition, to access the work line through another railing similar to the exit railing.
The mentioned exit railing is usually provided, in correspondence with the entrance opening for the moving handrail, with an inclined plane or ramp tending to separate the hand of the user from the handgrip-carriage which he or she is holding at the critical time in which the handrail penetrates the railing, in order to prevent accidents due to the “pinching” of the hand between the mentioned fixed and moving elements from occurring.
However, said inclined plane is not enough to provide the handrail with the sufficient safety, and practice shows that these types of accidents can occur.
In addition, the solution set forth by patent number 200603325 consists of arranging a stop in correspondence with the opening for accessing the inside of the railing, said stop being retractable and a longitudinal rod being joined thereto. An outer lid assembled on the fixed part of the railing which is laterally lowerable with respect to the latter between an open position and a closed position and an inner lid assembled on the fixed part of the railing which is also laterally lowerable with respect to the latter between an open position and a closed position are further arranged, said inner lid being connected to the outer lid so that the inner lid and the outer lid are opened together. The longitudinal rod and the stop are associated, with the possibility of longitudinal movement, to the outer lid, said longitudinal rod comprising locking means for the mentioned lid in a closed position.
In said solution, the mentioned lids are opened due to the movement of the stop driving the rod having a runner with wheels moving a housing made in the fixed base of the railing, said housings having an exit allowing, when the mentioned wheels move, the release of the outer lid which is automatically lowered due to the action of a hinge with a spring in its lowering shaft, the outer lid having at its upper part a pawl releasing the inner lid at the same time, which lid swings due to the effect of gravity.
Since two lids are needed, the mentioned solutions can have problems in the joint lowering of such lids, one of the lids occasionally being open and not achieving the initially desired effect (the complete opening of both lids at the same time so that there is no risk for the hand of the user of the walkway or mechanical stairs). In addition, the resetting of the system makes it necessary to close both lids in a special manner so that both of them are engaged by means of the mentioned pawl, their synchronization not being completely automated in the closing.
In addition, the mentioned solution had drawbacks inherent to its design since it was formed by two independent parts. With this system there is a risk of an incorrect operation due to interferences between the inner lid and the outer lid. The manufacture, assembly, adjustment and maintenance are difficult due to the high dimensional accuracy required in a device with these features. Likewise, the resetting of the system is complex as a result of the poor accessibility of the inner lid once it is actuated and due to the need of closing the two lids at the same time, the intervention of two operators being necessary to carry it out. It must also be added that it is necessary to open the outer lid so that the micro responsible for cutting off the power supply to the actuation of the walkway or stairs is activated.